Readily demountable display structures are in common use for displaying various objects at travelling exhibitions, trade shows, fairs and the like. The particular form of these display structures varies with the objects to be exhibited and the nature of the display facilities involved. These display structures are sometimes self-supporting and sometimes are supported from either or both the ceiling and walls of the display room involved. Thus, the display structures may comprise panels attached to tubular members or poles, which can form a self-supporting structure or can be suspended from the ceiling or connected to walls by fastening cables or other structural members. The various panel, pole, tube, cable or other structural elements are interconnected in various ways. One particularly useful device heretofore used to interconnect adjacent poles, tubes or panels is a two piece aluminum clamp with associated clamping bolt and nut and two slotted rubber insert members. The insert members are cylindrical and fit into a pair of corresponding parallel cylindrical sockets formed between the two confronting aluminum pieces into which the clamping bolt passes. The sockets, which are fixed in position relative to one another, are open on their outwardly forming sides to form socket entryways extending over an arc of roughly 90.degree.. The insert members, which are clamped in the sockets, have panel edge-receiving slots. The clamping device has a mirror-image symmetry on opposite sides of a plane extending through the clamping bolt axis and the socket entryways open onto the right and left lower quadrants of the sockets. When clamping pressure is released, the insert members in the sockets can be rotated into positions in the sockets so that the slots thereof open onto the entryways of the associated sockets over a range of angles corresponding roughly to the arcuate extents of the socket entryways, so that the number of structural orientation possible with this clamping device are limited accordingly.
Any sized panels may be used with this clamping device as long as the thickness of the panels match the size of the slots in the insert members. Glass panels as well as panels made of other materials can be interconnected by these clamping devices without special fasteners or slotted tracks. While poles may be used in conjunction with a panel extending in a plane including the axis of the pole or tubular member by removing an insert member from a socket and passing the pole or tubular member into the socket, such a use is very limited because the sockets of each clamping device are always parallel, and many display structures used with poles or tubular members extend in planes making an angle with each other or with an adjacent panel.
Thus, this prior clamping device described, which defines both sockets thereof between the same two confronting pieces, is useful primarily in building display structures comprising primarily a series of vertically oriented interconnected panels, and cannot, without the use of other types of fastener devices, interconnect a vertical panel and an elongated structural member like a pole or tubular member extending at right angles to the same, and so the variety of display structures which can be built using only these clamping devices having parallel sockets is greatly limited.
It is, therefore, an object of the present invention to provide a clamping device having the advantages of the clamping device just described, but without the limitations thereof, so that display structures having panels and/or elongated members of all types and orientations can be constructed therewith without the need for other kinds of fastener devices.